php json_decode and Jquery Nestable - php

Question

I'm using jquery Nestable (http://dbushell.github.io/Nestable/).
I'm trying to intercept data from it when I change order on mine nestable elements..
$('.dd').nestable().on('change', function() {
var json_text = $('.dd').nestable('serialize');
$.post("/includes/processes/core.php", {
cmd: 'nestable',
table: table,
data: json_text
}, function(response){
alert(response);
});
});
In core.php I've done:
$data = $_POST['data'];
$data = json_decode($data, true);
function parseJsonArray($jsonArray, $parentID = 0) {
$return = array();
foreach ($jsonArray as $subArray) {
$returnSubSubArray = array();
if (isset($subArray['children'])) {
$returnSubSubArray = parseJsonArray($subArray['children'], $subArray['id']);
}
$return[] = array('id' => $subArray['id'], 'parentID' => $parentID);
$return = array_merge($return, $returnSubSubArray);
}
return $return;
}
$readbleArray = parseJsonArray($data);
Than I've to manipulate this array but I can't go on because response is:
"json_decode() expects parameter 1 to be string, array given in core.php on line (where is "$data = json_decode($data, true;")"
If I change json_decode($data, true) with json_encode($data) this is the response:
"Invalid argument supplied for foreach() in core.php on line (where is "foreach ($jsonArray as $subArray);")"
Please Help me..

Answer 1

Try removing this line because $.post doesn't do json encoding.
$data = json_decode($data, true);

Answer 2

Use JSON.stringify. It will turn your javascript object into a JSON string, which will allow you to post it: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify
You can than decode it in PHP. To do this, in your jQuery code replace this:
data: json_text
With:
data: {json_text: JSON.stringify(json_text)}